Ingenieurwissenschaften

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Calculations for Functional Safety : Quantities, Formulas and Methods
(Hannover : Technische Informationsbibliothek, 2025-11-29) Brunnengräber, Thomas
Whereas in the past, functional safety hardly played a role in many industries, and in the others was essentially ensured by detailed design rules, driven by (negative) experiences, today the trend is moving away from fixed design rules to quantitative requirements and evidence. This undoubtedly promotes innovation and competition, but it also carries the risk of unsafe systems entering the market. The practice of the author as an assessor for functional safety shows again and again, that even experienced safety engineers find it difficult to perform correct calculations. This is often caused by a lack of understanding of the different variables, but just as often it is also due to a lack of knowledge about the calculation tools and methods used (especially FTA tools), coupled with an unjustifiably high level of trust in them. This introduction is primarily intended for prospective and experienced safety engineers, but also to mathematicians or computer scientists, who are entrusted with the development of calculation tools. Reference is occasionally made to standards, however, knowledge of these standards is not presumed. First, the parameters availability, reliability, failure density, failure rate, distribution functions, and MTTF, along with their mathematical foundations and dependencies, are presented in detail, and their practical significance is explained with examples. Then, it is shown how these parameters can also be calculated for complex systems using fault trees and Markov models.
Berechnungen zur Funktionalen Sicherheit : Größen, Formeln und Methoden
(Hannover : Technische Informationsbibliothek, 2025-11-29) Brunnengräber, Thomas
Während in der Vergangenheit die funktionale Sicherheit in vielen Branchen kaum eine Rolle spielte, und in den übrigen im Wesentlichen durch detaillierte Design-Regeln gewährleistet war, getrieben durch (negative) Erfahrungen, geht heute der Trend weg von festen Design-Regeln hin zu quantitativen Forderungen und Nachweisen. Dies fördert zweifellos die Innovation und den Wettbewerb, birgt jedoch das Risiko, dass unsichere Systeme auf den Markt kommen. Die Praxis des Autors als Gutachter für funktionale Sicherheit zeigt immer wieder, dass es selbst erfahrenen Sicherheitsingenieuren schwer fällt, korrekte Berechnungen anzustellen. Oft ist dafür mangelndes Verständnis der unterschiedlichen Größen ursächlich, genauso oft aber auch mangelnde Kenntnisse über die verwendeten Berechnungswerkzeuge und -methoden (insbesondere FTA-Tools), gepaart mit ungerechtfertigt großem Vertrauen in selbige. Diese Einführung richtet sich in erster Linie an angehende und erfahrende Sicherheitsingenieure, aber auch an Mathematiker oder Informatiker, welche mit der Entwicklung von Berechnungswerkzeugen betraut sind. Es wird gelegentlich Bezug auf Normen genommen, jedoch wird die Kenntnis dieser Normen nicht vorausgesetzt. Es werden zunächst die Größen Verfügbarkeit, Zuverlässigkeit, Ausfalldichte, Ausfallrate, Verteilungsfunktionen und MTTF und deren mathematische Grundlagen und Abhängigkeiten ausführlich dargestellt und deren praktische Bedeutung mit Beispielen erläutert. Dann wird gezeigt, wie diese Größen auch für komplexe Systeme mittels Fehlerbäumen und Markov-Modellen berechnet werden können.
Tin/Tin Oxide Nanostructures: Formation, Application, and Atomic and Electronic Structure Peculiarities
(Basel : MDPI, 2023-08-22) Liu, Poting; Sivakov, Vladimir
For a very long period, tin was considered one of the most important metals for humans due to its easy access in nature and abundance of sources. In the past, tin was mainly used to make various utensils and weapons. Today, nanostructured tin and especially its oxide materials have been found to possess many characteristic physical and chemical properties that allow their use as functional materials in various fields such as energy storage, photocatalytic process, gas sensors, and solar cells. This review discusses current methods for the synthesis of Sn/SnO2 composite materials in form of powder or thin film, as well as the application of the most advanced characterization tools based on large-scale synchrotron radiation facilities to study their chemical composition and electronic features. In addition, the applications of Sn/SnO2 composites in various fields are presented in detail.
Peculiarities in thermal transport of nanostructured silicon arrays with different morphology
([London] : Springer Nature, 2025-08-26) Sivakov, Vladimir; Liu, Poting; Chepela, Lesia; Lishchuk, Pavlo; Nkenfack, Isibert Marcel; Mandrolko, Viktor; Chaynes, Hadrien; Kuzmich, Andrey; Borovyi, Mykola; Lacroix, David; Isaiev, Mykola
This study explores the thermal conductivity of nanostructured porous silicon with different morphology produced by metal-assisted chemical etching of silicon wafers with different dopants, doping levels and crystallographic orientation. The wide range of morphological structures observed in the samples strongly depends on the initial wafer characteristics, a factor that cannot be neglected. While previous studies have demonstrated the qualitative capabilities of photoacoustic and Raman spectroscopy in characterizing nanostructured silicon, our work highlights the quantitative discrepancies that can arise when combining these techniques to investigate thermal properties. The differences in the results obtained using these methods can be attributed to the distinct nature of the information they provide: photoacoustic spectroscopy probes the effective thermal conductivity over larger areas, whereas Raman spectroscopy offers localized measurements. Furthermore, our Monte Carlo simulations provide insights into the morphological features of porous silicon that influence the interpretation of experimental data. This study underscores the importance of a comprehensive approach, combining both experimental and theoretical methods, to accurately assess the thermal transport properties of nanostructured materials.
Peculiarities in XPS spectra of Sn/SiO2 layers as an effect of surface charge
(Amsterdam [u.a.] : Elsevier, 2024-05-04) Liu, Poting; Freiberg, Katharina; Grinter, David C.; Sivakov, Vladimir
X-ray photoelectron spectroscopy based on synchrotron radiation was used to investigate the composition of the observed SnO2-x/Sn:SiO2-x thin layer grown by organometallic chemical vapour deposition on single-crystalline silicon wafer with additional argon ions etching treatment. Due to the formation of a thermodynamic anomaly during in situ layer growth, an efficient oxygen exchange between silicon and tin oxide phases occurs. The present study addresses the effect of localized surface charging and its influence on the obtained XPS core level spectra. We found that due to the high electrical conductivity of metallic tin and the direct coupling of tin particles to the silicon wafer, the XPS Sn 3d5/2 core level spectrum is not affected by the surface charge compared to the highly charged dielectric silicon oxide matrix, as observed for the XPS O 1 s and Si 2p core level spectra. Our results show that the core level spectra of Si 2p and O 1 s are shifted up to 3 eV due to the presence of uncompensated positive charge on the surface of the silica matrix. These results provide insight into the influence of surface charge effects on the analysis of conductor/insulator composite materials and contribute to the application of Sn-based materials in various application concepts related to energy and surface functionalization.
NEXAFS spectral peculiarities in Sn:SiO2 composite layer
(Amsterdam [u.a.] : Elsevier, 2025-06-23) Sivakov, Vladimir; Liu, Poting; Freiberg, Katharina; Yadav, Shivani; Grinter, David C.; Makarova, Anna
Synchrotron-based near-edge X-ray absorption fine structure (NEXAFS) spectroscopy has been used to investigate a novel Sn:SiO2 composite thin layer grown by organometallic chemical vapor deposition technique (CVD) on a single crystalline silicon wafer with additional treatment by argon ions. According to a previously reported thermodynamic anomaly, an efficient exchange of oxygen between the silicon and tin dioxide surfaces occurs during the growth of the metal oxide thin layer. The present study focuses on the visualization of the atomic and electronic structure of tin nanostructures localized in silica matrix. It is found that no significant chemical alterations are observed during argon ions treatment of the initial composite layer. The removal of atmospheric residues, which partially passivated defects in the highly defective SnO2-x top layer, did not significantly change the initial NEXAFS Sn M4,5 edge spectrum. Based on these results, we found that the main state in which tin nanoparticles localized in the amorphous silica matrix is the metallic state. In addition, based on the NEXAFS Si L2,3-edge studies, we found that silica is most associated with the stoichiometric structure of thermally deposited SiO2 layer with the presence of silicon suboxides. These results provide insights into the atomic and electronic structure of Sn:SiO2 composites and contribute to the possible implementation of such materials in various application concepts related to thermal energy storage and novel photonic devices.
Raman and fluorescence micro-spectroscopy applied for the monitoring of sunitinib-loaded porous silicon nanocontainers in cardiac cells
(Lausanne : Frontiers Media, 2022-08-09) Tolstik, Elen; Sivakov, Vladimir; Lorenz, Kristina; Gongalsky, Maxim Bronislavovich; Dierks, J.; Brand , T.; Pernecker , Moritz; Pervushin, Nikolay V.; Maksutova , D. E.; Gonchar, Kirill Aleksandrovich; Samsonova, J. V.; Kopeina, Gelina; Osminkina, Liubov A.
Nanomaterials are a central pillar in modern medicine. They are thought to optimize drug delivery, enhance therapeutic efficacy, and reduce side-effects. To foster this technology, analytical methods are needed to validate not only the localization and distribution of these nanomaterials, but also their compatibility with cells, drugs, and drug release. In the present work, we assessed nanoparticles based on porous silicon (pSiNPs) loaded with the clinically used tyrosine kinase inhibitor sunitinib for their effectiveness of drug delivery, release, and toxicity in colon cancer cells (HCT 116 cells) and cardiac myoblast cells (H9c2) using Raman micro-spectroscopy, high-resolution fluorescence microscopy, along with biological methods for toxicological effects. We produced pSiNPs with a size of about 100 nm by grinding mesoporous silicon layers. pSiNPs allowed an effective loading of sunitinib due to their high porosity. Photoluminescence properties of the nanoparticles within the visible spectrum allowed the visualization of their uptake in cardiac cells. Raman micro-spectroscopy allowed not only the detection of the uptake and distribution of pSiNPs within the cells via a characteristic silicon Raman band at about 518–520 cm−1, but also the localization of the drug based on its characteristic molecular fingerprints. Cytotoxicity studies by Western blot analyses of apoptotic marker proteins such as caspase-3, and the detection of apoptosis by subG1-positive cell fractions in HCT 116 and MTT analyses in H9c2 cells, suggest a sustained release of sunitinib from pSiNPs and delayed cytotoxicity of sunitinib in HCT 116 cells. The analyses in cardiac cells revealed that pSiNPs are well tolerated and that they may even protect from toxic effects in these cells to some extent. Analyses of the integrity of mitochondrial networks as an early indicator for apoptotic cellular effects seem to validate these observations. Our study suggests pSiNPs-based nanocontainers for efficient and safe drug delivery and Raman micro-spectroscopy as a reliable method for their detection and monitoring. Thus, the herein presented nanocontainers and analytical methods have the potential to allow an efficient advancement of nanoparticles for targeted and sustained intracellular drug release that is of need, e.g., in chronic diseases and for the prevention of cardiac toxicity.
Multi-Material Topology Optimization for IPM Machine with Efficient Rare-Earth PM Utilization
(New York, NY : IEEE, 2025-10-14) Mahmoud, Mohamed Reda; Ibrahim, Mohamed N.; Sergeant, Peter
This paper presents a multi-material topology optimization (TO) to efficiently utilize rare-earth permanent magnet (REPM) material and improve the machine performance. The proposed approach employs a density-based TO method to optimize the multi-material distribution inside the rotor domain. The TO algorithm optimally redistributes air, silicon-steel, and REPM. The objective function of the TO is to maximize the average torque of the IPM motor while constraining the material volume of both silicon-steel and REPM to below that utilized in the conventional design. The results demonstrate that multi-material TO is a highly effective strategy for developing a new generation of sustainable electric machines. The topology optimized configuration achieved an approximate 4% increase in torque density while reducing the amount of REPM used by 12.5%. Moreover, the amount of silicon steel required for the optimized rotor is 9% lower than the conventional design.
Topology Optimization for Enhancing Electric Machine Performance: A Review
(New York, NY : IEEE, 2024-09-01) Mahmoud, Mohamed Reda; Ibrahim, Mohamed N.; Sergeant, Peter
Exploring the design space is essential in the pursuit of developing high-performance and power-dense electric machines. This article explores the transformative potential of topology optimization (TO) in enhancing the performance of electric machines. Conventional techniques for optimizing the design of electric machines use optimization algorithms to determine geometric variables within a predefined range. However, these methods are limited by manufacturing constraints and the designer's expertise in parameterization. On the other hand, topology optimization aims to enhance the performance of electric machines by manipulating the distribution of materials as a design factor. The enhancement is facilitated by additive manufacturing (AM), particularly via the manufacturing of intricate metal parts. In this paper, the main concepts of topology optimization in electric machines are reviewed. Firstly, the requirement for topology optimization is illustrated, and both the achievements and challenges of this technique over the traditional parametric optimization are described. Then, a description is given of different topology optimization methods that were reported in the literature. Finally, the development opportunities of this technology are shown in the electric machine design field.
Topology Optimization for a Magnetic Actuator Using Different Gradient-Based Solvers
(New York, NY : IEEE, 2025-01-13) Mahmoud, Mohamed Reda; Ibrahim, Mohamed N.; Sergeant, Peter
This paper presents a comparative study on the performance of density-based topology optimization using different gradient-based solvers. Three common solvers are employed: the method of moving asymptotes (MMA), interior point optimizer (IPOPT), and sparse nonlinear optimizer (SNOPT). The gradient solvers are compared regarding the convergence behaviour, computational time, and solution quality, i.e. maximizing the attractive force, when topology optimization is used to design a magnetic actuator as a case study. The results provide valuable insights into the strengths and limitations of MMA, IPOPT, and SNOPT in solving topology optimization and offering guidance for selecting the appropriate solvers. The results proved that SNOPT is suitable for largescale problems as it has fast convergence and low computation time compared to MMA and IPOPT solvers. Further, IPOPT is not suitable for large-scale problems due to high computation time and large amounts of intermediate materials, i.e. regions where the density function differs from 0 and 1. Moreover, the quality of the optimal solution is only slightly affected by the used solver.
Reducing AC Joule Losses in Hairpin Windings of Electric Machines: Strategies for Minimizing Losses Due to Radial and Tangential Flux
(New York, NY : IEEE, 2025-10-22) Bekele, Yitbarek; Korolova, Olga; Biebighäuser, Andreas; Akbar, Siddique; Ebrahimi, Amir; Ponick, Bernd
This paper presents a comprehensive analysis of conductor design strategies to reduce joule losses in hairpin windings of high-speed permanent magnet synchronous machines (PMSMs). With the increasing demand for high torque density, efficiency, and high-speed operation in electric vehicles and aircraft, minimizing these losses is crucial. Starting with a reference winding layout, various loss mechanisms due to radial and tangential flux components are investigated using finite element analysis (FEA) under both no-load and short-circuit conditions. Design variants including adjustments to conductor geometry, slot opening shapes, layer-specific conductor height tuning and segmented conductor designs with overhang twisting are explored. The findings are relevant for improving the performance and manufacturability of electric machines, with additive manufacturing offering new design opportunities for enhanced efficiency and lower losses.
The Evolution and Future of Composite Construction in Light Aircraft
(Hannover : Technische Informationsbibliothek, 2025) Wu, William
Within this study the historical development, current applications and future topics of light aircraft construction shall be analyzed. It describes the evolution of used materials and construction methods starting from traditional materials such as wood and aluminum to advanced composite materials. Furthermore, the different types of composite materials and construction methods are categorized, their advantages and disadvantages are discussed. The implementation in current aircraft models by leading manufacturers such as Diamond Aircraft, Cirrus, and Elixir is presented. Further, the challenges that likely arise with the adoption of advanced composites in general aviation are discussed and finally emerging trends and technologies that may be adapted in future aircraft construction are described.
Additively Manufactured Spoke-type Permanent Magnet Rotors: Solutions to Multidisciplinary Design Challenges and Comparison with Traditional Design
(New York, NY : IEEE, 2025-10-09) Ajamloo, Akbar Mohammadi; Tiismus, Hans; Kallaste, Ants; Ibrahim, Mohamed N.; Sergeant, Peter
Sustainability in electrical machines demands minimizing material waste, eliminating rare-earth permanent magnets (PMs), and improving efficiency and reliability. Additive manufacturing (AM) offers a promising pathway toward these goals by enabling near-zero material waste, streamlined production, and enhanced design freedom. This study leverages the compatibility of spoke-type rotor configurations with nonrare-earth PMs and the unique advantages of AM to achieve a highly sustainable design. The paper proposes innovative solutions to address the existing challenges of using AM for developing ferrite PM rotor topologies and provides a comprehensive comparison with traditional laminated topology. A novel technique is presented, reducing torque ripple from 42% to 16%, and voltage THD from 11% to 5%. The proposed solution not only maintains the average torque but also avoids added manufacturing complexity and cost, unlike skewing techniques. Moreover, a new grooving technique is implemented, reducing the eddy current loss in the bulk rotor by more than 40%. A spoke-type design with open bridges is selected over the closed-bridge design, and a comprehensive multidisciplinary analysis is conducted. Two spoke-type rotors are 3D printed, and one traditional laminated rotor is manufactured. The experimental comparisons show that the proposed 3D printed rotors outperform the laminated design in terms of torque ripple, voltage THD, and material usage, while offering comparable power rating and back-emf.
Hydrogen in General Aviation for an efficient and sustainable future
(Hannover : Technische Informationsbibliothek, 2025-10-01) Wu, William
As global climate change accelerates, the aviation sector faces increased urgency to reduce carbon emissions in pursuit of the global goal of Net Zero 2050. Hydrogen has emerged as a promising fuel for future green aviation, offering high energy density per unit mass and virtually zero carbon dioxide emissions. The study examines two major pathways of hydrogen implementation in general aviation: combustion in piston engines and hydrogen fuel cells. Within combustion systems, both spark-ignited and compression-ignited (by using a kerosene jet) engines are analyzed, their pros and cons. The challenges they encounter are also addressed, including premature ignition, NOx emissions, and backfiring. Hydrogen fuel cells are evaluated efficiency across varying load conditions and operating temperatures, cooling systems, and long-life spans. At the same time, major drawbacks, including weight, storage limitations, and design complexity, are also accounted for. Hydrogen use in internal combustion chambers shows a practical short-term solution as it has a high technology readiness level and requires minimal modifications to existing engines. On the contrary, Hydrogen fuel cells hold the most promising future, but are hindered by current technological barriers. The study presents a detailed comparison chart between internal combustion engines (ICE) and Hydrogen fuel cells, including efficiencies, emissions and complexity. Finally, the study concludes the importance of hydrogen in green aviation, while highlighting the need for infrastructure development and innovations in hydrogen storage.
Dauborn Extraktkonzentration : Sedimentationsarme Kaffee-/ Tee- Extraktkonzentrierung : Erhöhung der Verarbeitungs- und Rohstoffeffizienz durch neue Verfahrenskette
(Hannover : Technische Informationsbibliothek, 2025) Stern, Andreas; Reinhardt , Eugen; Reinhardt, Eugen; Stern, Andreas
Das Dauborn Verfahren ermöglicht durch den Einsatz einer dynamischen Mikro-/Ultrafiltration direkt nach der Extraktion der Röstkaffeebohnen, eine weitgehend sedimentationsfreie Konzentrierung des Kaffee-Rohextraktes. Die Filtrierung wird kontinuierlich betrieben. Durch den Verzicht auf die Abscheidung großmolekularer Bestandteile durch einen Separator, kann diese aufwendige Technologie durch das Verfahren verdrängt werden. Neben der Senkung der Betriebskosten (Energie, Wartung und Instandhaltung) können durch das neue Verfahren die Verarbeitungsverluste wesentlich reduziert werden. Ungelöste Extraktbestandteile, die bei der Separierung als Separatorrückstände ausgetragen und entsorgt werden müssen, können durch die Verfahrenskombination im Flüssigkaffee gehalten und stabilisiert werden. Zusammen mit anderen Effekten, kann dadurch die Rohstoffausbeute und Verarbeitungseffizient des Flüssigkaffees wesentlich erhöht werden. Die vorgeschaltete dynamische Mikro-/Ultrafiltration verbessert die Standzeiten der nachfolgenden Konzentrierungsanlagen (Eindampfung oder Umkehrosmose) durch die Reduzierung von Ablagerungen. Des Weiteren werden Spül- und Reinigungsintervalle reduziert. Durch diese Effekte werden die Betriebskosten deutlich gesenkt. Beim Einsatz einer Umkehrosmose zur Extraktkonzentrierung lassen sich nach der Vorbehandlung durch eine Mikro-/Ultrafiltration, deutlich höhere Endkonzentrationen erreichen. Ein prozessintegrierter Homogenisierungsschritt stellt sicher, dass Sedimentationen im Endprodukt vermieden werden. Dies ermöglicht eine weitgehend rückstandsfreie Verarbeitung.
Enhanced findability and reusability of engineering data by contextual metadata
(Cambridge : Cambridge University Press, 2023) Altun, Osman; Oladazimi, Pooya; Wawer, Max Leo; Raumel, Selina; Wurz, Marc; Barienti, Khemais; Nürnberger, Florian; Lachmayer, Roland; Mozgova, Iryna; Koepler, Oliver; Auer, Sören
Complex research problems are increasingly addressed by interdisciplinary, collaborate research projects generating large amounts of heterogeneous amounts of data. The overarching processing, analysis and availability of data are critical success factors for these research efforts. Data repositories enable long term availability of such data for the scientific community. The findability and therefore reusability strongly builds on comprehensive annotations of datasets stored in repositories. Often generic metadata schema are used to annotate data. In this publication we describe the implementation of discipline specific metadata into a data repository to provide more contextual information about data. To avoid extra workload for researchers to provide such metadata a workflow with standardised data templates for automated metadata extraction during the ingest process has been developed. The enriched metadata are in the following used in the development of two repository plugins for data comparison and data visualisation. The added values of discipline-specific annotations and derived search features to support matching and reusable data is then demonstrated by use cases of two Collaborative Research Centres (CRC 1368 and CRC 1153).
Enhanced Design and Electromagnetic Analysis of Synchronous Reluctance Machines Using Multi-Material Additive Manufacturing
(New York, NY : IEEE, 2025) Akbar, Siddique; Bekele, Yitbarek Tedla; Ebrahimi, Amir; Ponick, Bernd
This article comprehensively investigates the design and simulation of synchronous reluctance machines (SynRMs) using multi-material additive manufacturing (MMAM) methods. The main goal is to improve the electromagnetic performance of the machine by strategically utilizing various materials in the rotor's edge bridges to reduce quadrature inductance Lq. A comparative analysis is led on various combinations of magnetic and non-magnetic materials, examining conventionally built machines with single materials alongside additively manufactured machines with both single and multiple materials. A demonstrator machine is built to analyze and determine essential performance parameters, emphasizing the optimization of the rotor. The research establishes an optimized rotor model to enhance electromagnetic performance and examines the operational impacts on electromagnetic torque and torque oscillations. Analytical and simulation findings illustrate the capability of multi-material additive manufacturing to improve the performance of conventional electric machines.
Outstanding Platinum Recovery by Electrochemical Cathodic Leaching and Redeposition in One-Pot 2 M HCL Solution
(Bristol : IOP Publishing, 2025-07-16) Sakthivel, Mariappan; Gandharva, Reshma; Schreiber, Christopher; Drillet, Jean-Francois
Selective Pt recovery from spent Pt/C gas diffusion electrodes (GDE) is essential for sustainable proton exchange membrane fuel cell and electrolysis industry. This study presents a promising, environmentally friendly approach using pulsed electrochemical cathodic leaching (ECCL) and subsequent electrochemical cathodic deposition (ECCD) in one pot diluted HCl solution. The parameters of ECCL pulse signal were optimized by varying electrolyte concentration, cell voltage, duty cycle, pulse number, and pulse sequence. For aging of GDE, a standard accelerated degradation tests protocol was applied. The amount of dissolved Pt in the electrolyte was evaluated by UV–vis absorption peak intensity at 260 nm that is assigned to Pt (IV) chloro complex ions. A Pt dissolution rate of 99.8% from fresh and aged GDE was achieved in 2 M HCl by applying cell voltage of “only” −3 V (cathode potential: −0.55 V vs RHE) and combining long and short pulse voltage sequences. Remaining Pt in the electrode were determined from electrochemical surface area and thermogravimetric analysis profiles confirming UV–vis results. Finally, proof of concept of one-pot Pt recovery from ECCL electrolyte by means of ECCD step was demonstrated.
Investigation of Different Pole Configurations in New Asymmetric Permanent Magnet Synchronous Reluctance Machines
(New York, NY : IEEE, 2025-01-13) Ajamloo, Akbar Mohammadi; Ghaheri, Aghil; Ibrahim, Mohamed N.; Sergeant, Peter
This paper investigates the impact of pole number and configuration on key performance characteristics of a new family of asymmetric permanent magnet synchronous reluctance machines (PMSynRMs). New variants of asymmetric PMSynRMs are presented here which integrate distinct interior PM (IPM) poles and reluctance poles into a single lamination. The torque enhancement principle relies on segregating the net torque into components generated by each pole type. Torque enhancement is achieved by optimally shifting the IPM poles relative to the reluctance poles, aligning the torque peaks generated by each pole type. A comprehensive comparative analysis is conducted between the proposed asymmetric and conventional topologies, with identical PM volume, copper loss, frequency, and frame size. The analysis evaluates torque production capability, unbalanced magnetic forces, torque ripple, losses, and power factor. The results reveal that the asymmetric PMSynRMs offer improved torque, power factor, and reduced torque ripple compared to conventional designs for pole numbers 4, 6, 8, and 10. However, some asymmetric designs exhibit the drawback of unbalanced magnetic forces, which should be taken into consideration. Finally, an asymmetric PMSynRM is prototyped and tested to verify the simulation results.
Properties of Additively Manufactured Soft and Hard Magnetic Cores for Electrical Machines: Methods and Materials − A Review
(New York, NY : IEEE, 2025-05-20) Ajamloo, Akbar Mohammadi; Ibrahim, Mohamed N.; Sergeant, Peter
Additive Manufacturing (AM) is an emerging topic in the field of electrical machines (EMs), offering the potential to overcome challenges imposed by conventional manufacturing methods. This paper provides an overview of various AM methods and materials used to manufacture soft and hard magnetic cores for EMs, with a particular focus on their multiphysics properties. Since each AM method involves unique processes—such as particle bonding, melting, or sintering—the resulting microstructural properties of the printed cores differ, leading to varied multi-physics characteristics that require indepth study. The paper outlines both the benefits and challenges associated with AM techniques and materials. Importantly, it explores the detailed properties of Fe-Si and Fe-Co soft magnetic cores as well as hard magnetic cores including NdFeB, ferrite, and alnico printed through different AM methods, comparing them to traditional laminations and commercial hard magnets.

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